Process for improving cotton



tilt) Patented Dec. 3,1929- UNITED STATES LEON LILIENFELD, F VIENNA,AUSTRIA- PROCESS FOR IMPROVING COTTON No Drawing. Application filedFebruary 3, 1927,

llhere are known processes of treating vegetable fibrous materials, suchas cotton fabric and the like, with alkali and carbon bisulphide, partlyin order to convert these materials into a parchment-like product,partly to provide them with a durable dressing. hese processes consistin treating the fibrous materials, particularly fabrics, with strongalkali solution and them subjecting them to m the action of carbonbisulphide in vapour form, or in treating the material first withconcentrated alkali solution, then with carbon-bisulphide and finallymercerizing under tension.

According to my invention very valuable properties are imparted tocotton in hank or fabric form when, without previously converting itinto alkali-cellulose, it is treated simultaneously with alkali solutionand carno bon bisulphide, undiluted or diluted ,with suitable diluents(for example, benzene, chloroform, petrol, petroleum ether, ligroin,carbon tetrachloride or the like). This may be done either byimpregnating the cotton or the material consisting of or containingcotton with diluted or undiluted carbon bisulphide and then similarlytreating with alkali solution or by subjecting the cotton material tothe action of alkali solution to which carbon bisulphide is added beforeor "after the introduction of the cot-ton.

According to the particular nature of the cotton material and theduration of the action of the carbon bisulphide in presence of alkalisolution, there are obtained according to the present process eitherhighly-translucent effects with a very silky lustre, or a more or lessstiffening finishing or both. Woollike appearance and" feel may also begiven the material treated according to the process,

The cotton may be treated according to the invention in the form offabric, of yarns, in hanks or in the form of cops or warps.

The cotton or the material consisting'of or containing cotton, may betreated by the present process raw or after preliminary treatment .(forexample boiled, 'wetted or not wetted, unbleached or bleached withoxidizing or reducing bleaching agents, mercerized or not mercerized).

Serial No. 165,749, and in Austria May 23, 1923.

It may also be treated previously with a hydrolyzing or gelatinizingagent, for example a strong mineral acid, such as sulphuric acid of49-60 Baum specific gravity or phosphoric acid of 5.557 Baum or higherspecific gravity, or hydrochloric acid of 24 Baum specific gravity, ornitric acid of 43-46 Baum or higher specific gravity, or hot solution ofzinc chloride of 60 Baum specific gravity or an ammoniacal solution 60of cupric oxide of considerable concentration.

By. reserving certain portions in accordance with known methods (forexample by the application of substances adapted for this purpose, suchas albumimgum, acids and the like) pattern effects may be obtained bythe present process.

Mixed goods, that is to say, goods composed of vegetable and animalfibres, may also be subjected to the present process.

By suitable selection of the operating con- 'ditions there may beobtained in accordance with the present process silky effects surpassingthose obtained by the usual mercerizlng methods, as well as wool-like orspringy of fects.

To obtain the silky lustre, stretching of the goods is essential. It isimmaterlal 'whether the tension isapplied before or after the treatmentwith alkali solution in presence 30 of carbon bisulphide. When thestretching of the goods is omitted the silky lustre effects disappearandthe goods assume a springy conditionand resemble wool to a very markeddegree.

The followingexam'ples illustrate the invention:

1. Bleached or unbleached mercerized or unmercerized cotton fabric istreated under tension with carbon bisulphide undiluted or dilutedwith'benzene (for example 1-5 parts of benzene to 1 part of carbonbisulphide) for some seconds up to .a quarter of an hour. Then, wheredesired after squeezing outthe excess carbon bisulphide,the fabric istreated as with caustic soda solution of 14-20 per cent strength forsome minutes up to several hours.

2. Cotton fabric under tension is introduced into a mixture of causticsoda solution of 10-1 p ent t g w h L -3, per .00

cent of carbon bisulphideand treated with this mixture for some minutesup to several hours.

3. The mode of operation is as in the foregoing examples, except thatbefore being subjected to the present processthe fabric is previouslytreated with a strong sulphuric acid. If a sulphuric acid of 4950 Baumspecific gravity is used for this purpose, the treatment therewith, atroom temperature, may be continued for a few seconds up to some minutesor even longer. If a stronger sulphuric acid is used, for example one of52-54: Baum specific gravity, the treatment is to occupy only a fewseconds, if the sulphuric acid is of room temperature. If thesulphuricacid is cooled to 0 C. or lower, the treatment may be longer.

The treatment with sulphuric acid may be preceded by a mercerizing ofthe fabric, for example with caustic soda solution of 10 per centstrength at low temperatures or with a strong caustic soda solution, forexample of 18-40 per cent strength at room temperature.

In order to bringv about the production of the wool-like effects orwooly appearanceof the goods treated, it only becomes necessary to omitwhat was said above to .be essential to the production of the silkyefi'ects, namely the treatment of the goods under tension or in thestretched condition. Therefore, if the wool-like appearance or springycondition of the goods treated is desired, it may be produced sim ly byomitting the stretching or tension re erred to in the above specificexamples.

The cotton fabric treated in accordance with the present process may, ofcourse, be washed'or acidified and washed and dried in the usual way..It may also be dried or steamed before washing.

All the secondary ope-rations usual in mer--.

cerizing or proposed therefor may be applied to the present process, forexample lustering, printing, etc. V v The finished fabrics may, ifdesired, be calendered, schreinered, beatled or the like. 7 The termcotton in the following claims comprises cotton in the form of purecotton alkali cellulose, simultaneously with caustic alkali solution andcarbon bisulphide.

2. The process of imparting wool-like effe'cts to cotton by treatingwith caustic alkali and carbon bisulphide which comprises treatingcotton in a substantially unstretched or free from tension conditionfirst with carbon bisulphide and then with caustic alkali solution.

3. The process of imparting wool-like effects to cotton by treating withcaustic alkali and carbon bisulphide which comprises reacting uponcotton in a substantially unstretched condition with a mixture ofcaustic alkali solution and carbon bisulphide.

4. The process of producingwool-like effects in cotton goods whichcomprises subjecting cotton goods to the simultaneous action of carbonbisulphide and a hydroxide of an alkali metal while maintaining thecotton goods during such action in a substantia-lly unstretchedcondition or in a state substantially free from tension.

5. The process of imparting wool-like eifects to cotton .by treatmentwith alkali and carbon disulphide which comprises reactingsimultaneously on cotton in a substantially unstret'ched or free fromtension condition with caustic alkali and carbon disulphide.

6. The process of imparting wool-like efiectsto cotton by treatment withcaustic alkali and carbon bisulphide which comprises ,treating cotton ina substantially unstretched,

or free from tension condition, and while substantially free frompreviousl formed alkali cellulose, first with carbon bisulphide and thenwith aqueous caustic alkali solution.

7. The process of imparting wool-like effects to cotton by treatmentwith caustic alkali and carbon bisulphide which comprises subjecting thecotton in a substantially unstretched or free from tension condition,and while substantially free from previously formed alkali cellulose, tothe action of a mixture of carbon bisulphide and aqueous caustic alkali.

In testimony whereof I aflix my signature.

LEON LILIENFELD.

or mixed fabrics, ofyar'ns for example in 5 hanks or cops or warps.

The expression"mercerizing agent? in the following claims comprisesalkali lye or strong mineral acids.

This application is in part a continuation of my application Serial No.712,473, filed May 10, 1924.

I claim: y

1. The process of imparting wool-like effects to cotton by treatmentwith caustic alkali and carbon bisulphide, which comprises treatingcotton in a substantially unstretched or free from tension condition,without previous conversion 1nto caustic

